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| | FLAC 1.1.4
Updated: 15 Apr 2007 | | 2.45MB | Downloads: 157903 |
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FLAC stands for Free Lossless Audio Codec. Grossly oversimplified, FLAC is similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player (or your car or home stereo, see links to the right for supported devices) just like you would an MP3 file.
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The FLAC project consists of :
- the stream format
- reference encoders and decoders in library form
- flac, a command-line program to encode and decode FLAC files
- metaflac, a command-line metadata editor for FLAC files
- input plugins for various music players
Features of FLAC 1.1.4 :
• Lossless: The encoding of audio (PCM) data incurs no loss of information, and the decoded audio is bit-for-bit identical to what went into the encoder. Each frame contains a 16-bit CRC of the frame data for detecting transmission errors. The integrity of the audio data is further insured by storing an MD5 signature of the original unencoded audio data in the file header, which can be compared against later during decoding or testing.
• Fast: FLAC is asymmetric in favor of decode speed. Decoding requires only integer arithmetic, and is much less compute-intensive than for most perceptual codecs. Real-time decode performance is easily achievable on even modest hardware.
• Hardware support: Because of FLAC's free reference implementation and low decoding complexity, FLAC is currently the only lossless codec that has any kind of hardware support.
• Streamable: Each FLAC frame contains enough data to decode that frame. FLAC does not even rely on previous or following frames. FLAC uses sync codes and CRCs (similar to MPEG and other formats), which, along with framing, allow decoders to pick up in the middle of a stream with a minimum of delay.
• Seekable: FLAC supports fast sample-accurate seeking. Not only is this useful for playback, it makes FLAC files suitable for use in editing applications.
• Flexible metadata: New metadata blocks can be defined and implemented in future versions of FLAC without breaking older streams or decoders. Currently there are metadata types for tags, cue sheets, and seek tables. Applications can write their own APPLICATION metadata once they register an ID
• Suitable for archiving: FLAC is an open format, and there is no generation loss if you need to convert your data to another format in the future. In addition to the frame CRCs and MD5 signature, flac has a verify option that decodes the encoded stream in parallel with the encoding process and compares the result to the original, aborting with an error if there is a mismatch.
• Convenient CD archiving: FLAC has a "cue sheet" metadata block for storing a CD table of contents and all track and index points. For instance, you can rip a CD to a single file, then import the CD's extracted cue sheet while encoding to yield a single file representation of the entire CD. If your original CD is damaged, the cue sheet can be exported later in order to burn an exact copy.
• Error resistant: Because of FLAC's framing, stream errors limit the damage to the frame in which the error occurred, typically a small fraction of a second worth of data. Contrast this with some other lossless codecs, in which a single error destroys the remainder of the stream.
Changes from FLAC 1.1.3 to FLAC 1.1.4 :
• General:
- Improved compression with no change to format or decrease in speed.
- Encoding and decoding speedups for all modes. Encoding at -8 is twice as fast.
• flac:
- Improved compression with no change to format or decrease in speed.
- Encoding and decoding speedups for all modes. Encoding at -8 is twice as fast.
- Added a new option -w,--warnings-as-errors for treating all warnings as errors.
- Allow --picture option to take only a filename, and have all other attributes extracted from the file itself.
- Fixed a bug that caused suboptimal default compression settings in some locales (SF #1608883).
- Fixed a bug where FLAC-to-FLAC transcoding of a corrupted FLAC file would truncate the transcoded file at the first error (SF #1615019).
- Fixed a bug where using -F with FLAC-to-FLAC transcoding of a corrupted FLAC would have no effect (SF #1615391).
- Fixed a bug where new PICTURE metadata blocks specified with --picture would not be transferred during FLAC-to-FLAC transcoding (SF #1627993).
• metaflac:
Allow --import-picture-from option to take only a filename, and have all other attributes extracted from the file itself.
• plugins:
- Fixed a bug in the XMMS plugin where Ctrl-3 (file info) would cause a crash if the file did not exist (SF #1634941).
build system:
Fixed a makefile linkage bug with libogg (SF #1611414).
Added pkg-config files for libFLAC and libFLAC++ (SF #1647881).
Added --disable-ogg option for building without Ogg support even if libogg is installed (SF #1196996).
• libraries:
Completely rewritten bitbuffer which uses native machine word size instead of bytes for dramatic speed improvements. The speedup should be most dramatic on CPUs with slower byte manipulation capability and big-endian machines.
Much faster Rice partition size estimation which greatly speeds encoding in higher modes.
Increased compression for all modes.
Reduced memory requirements for encoder and decoder.
Fixed a bug with default apodization settings that were erroneous in some locales (SF #1608883).
• Interface changes:
• libFLAC:
(behavior only) FLAC__stream_encoder_set_metadata() now makes a copy of the "metadata" array of pointers (but still not copies of the objects themselves) so the client does not need to maintain its copy of the array after the call.
• Related downloads:
- CoreFlac: is a DirectShow-Decoder for the Flac audio codec...
- Ogg Vorbis: is a high-quality lossy audio codec which is free of intellectual property restrictions (like those surrounding MP3).
- WavPack: is a completely open audio compression format providing lossless, high-quality lossy, and a unique hybrid compression mode.
- Lossless Audio (La): is a Lossless Audio compression codec. In contrast to formats such as MP3, La reduces the size of music without affecting the quality...
- Shorten: is an audio compression scheme that is used to compress audio files losslessly.
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